Opening mechanism

ABSTRACT

A single-handed opening mechanism for a container ( 1 ) holding a pourable substance comprising an elongate sealing element ( 2 ) which is moveable from a first closed position to a second open position. The elongate sealing element ( 2 ) is deformable and moves from the first closed position to the second deformed open position by the application of a squeezing force applied by the user&#39;s hand substantially along the length of the elongate sealing element ( 2 ).

[0001] The present invention relates to a single-handed openingmechanism for a container holding a pourable substance. The invention isparticularly suitable for single-portion containers such as those usedfor adding milk to tea and coffee.

[0002] The most common liquid containers used, for example, for addingmilk to tea and coffee typically comprise a plastic container and a foillid. To open containers of this type, a two-handed operation isrequired, with one hand holding the container and the other pulling offthe lid before the contents can be poured out. An object of the presentinvention is to provide a container that can be opened by a single handonly.

[0003] Other liquid containers of the single-handed opening type, forexample single portion sachets, involve squeezing the container tocreate a tensile force on a weakened portion, causing it to rupture. Thekey feature of this type of container is that the forces applied to thecontainer are transferred through the liquid within the container torupture said container. Such an arrangement suffers from thedisadvantage that if the rupture is caused by an increase in thepressure of the liquid, the liquid will also pass through the ruptureunder pressure and result in the contents jetting out of the containerin an uncontrolled manner.

[0004] EP-A-0078761 discloses an example of such a sachet typecontainer. This document discloses a sealed container comprising twolayers of thermoplastic film heat sealed together, a v-shaped area beingformed as part of the heat sealed pattern, with the apex of the vdirected toward the interior of the container. When pressure is appliedto the container, such as by squeezing it, the heat seal ruptures,beginning at the apex of the v, and continuing through the heat seal ina well defined path. As a result, the contents of the container, such asan individual serving of ketchup, can be dispensed from the container.

[0005] A more sophisticated arrangement of a sachet type container isdescribed in U.S. Pat. No. 5,131,760 which discloses a package which maycontain a fluid material which is capable of being discharged from thepackage by the application of manual pressure from a thumb andforefinger to the package so as to cause the package to burst in acontrolled fashion to discharge the fluid material contained within thepackage. The package comprises a second chamber which receives the fluidmaterial discharged from a first containing chamber after the firstcontaining chamber is burst by manual pressure. This second chamberfurther has a seal which will burst under a reduced amount of manualpressure than required to burst the first containing chamber, so as tocontrol the rate and manner of discharge of the fluid from the package.

[0006] As an alternative to a sachet which dispenses its contentsthrough a ruptured heat seal, WO 01/17875 discloses a sachet which has asemi-rigid member with a weakened region formed thereon so that uponbending across the weakened region the semi-rigid member will fracturealong the weakened region. The sachet also has a reservoir formed byoverlaid first and second flexible film layers which are adapted tocontain a flowable substance. In use, fracturing the weakened regionallows the flowable substance to be dispensed.

[0007] All the single-handed opening type arrangements described abovesuffer from the disadvantage that the container is ruptured and thecontents are discharged simultaneously. This results in an uncontrolleddischarge.

[0008] An alternative opening mechanism for a liquid container isdescribed in U.S. Pat. No. 3,175,749 which discloses a carton having apour spout which opens when the carton is squeezed in the vicinity ofthe pour spout and automatically closes when the pressure is released.

[0009] The disadvantage with the above carton arrangement is that inorder to open the pour spout the body of the container must be squeezed.Squeezing the body of the carton transmits forces to the liquidcontained within, causing random motion of the liquid. Further, as thebody of the carton is squeezed the height of the liquid contained withinwill rise. The random motion of the liquid combined with an overall risein the height of the liquid as the spout is opened may result inspillage. Such an effect will be increased as the container size reducessince there will be less space between the liquid surface and the spout.

[0010] The object of the present invention is to provide an openingmechanism which addresses the disadvantages of the prior artarrangements described above i.e. a single-handed opening mechanism fora container holding a pourable substance wherein the container isopenable while imparting a negligible amount of pressure on the contentswithin. Such a mechanism has the advantage over the prior artarrangements that the container may be first opened and thensubsequently poured in a controlled manner thereby limiting the chanceof spillage. Pourable substances may include low viscosity liquids suchas milk, medium viscosity liquids such as ketchup sauces and face/bodylotions, high viscosity and non-Newtonian liquids such as clotted creamand toothpaste, liquids containing solid particles such as Frenchdressings and granular solids such as salt. It may be necessary,particularly in the case of high viscosity liquids, to squeeze thecontainer body after opening in order to controllably dispense thecontents.

[0011] According to the present invention there is provided asingle-handed opening mechanism for a container holding a pourablesubstance comprising an elongate sealing element which is moveable froma first closed position to a second open position wherein the elongatesealing element is deformable and moves from the first closed positionto the second deformed open position by the application of a squeezingforce applied by the user's hand substantially along the length of theelongate sealing element.

[0012] Preferably, the elongate sealing element is resealable followinguse.

[0013] Preferably, the elongate sealing element comprises anopenable/closable portion, said openable/closable portion being closedin the first position and said openable/closable portion defining anaperture in the second position.

[0014] Preferably, said openable/closable portion comprises asubstantially cross shaped slit in the closed position.

[0015] Preferably, said openable/closable portion comprises a pluralityof hinge points.

[0016] Preferably, said aperture is substantially diamond shaped.

[0017] Preferably, said elongate sealing element consists of first andsecond substantially rigid portions and wherein the openable/closableportion is located between said first and second substantially rigidportions.

[0018] Advantageously, said elongate sealing element further comprises alocking element for locking the mechanism in the first closed position.

[0019] Preferably, said locking element is constrained to slide on theelongate sealing element.

[0020] Preferably, the elongate sealing element further comprises abreakable diaphragm, said breakable diaphragm being broken on movingfrom the first closed position to the second open position.

[0021] Preferably, the elongate sealing element is fabricated from aplastic material.

[0022] Alternatively, the elongate sealing element is fabricated from acardboard material.

[0023] The present invention also provides a container comprising asingle-handed opening mechanism.

[0024] The present invention also provides a method of manufacturing thesingle-handed opening mechanism for a container holding a pourablesubstance, the method comprising moulding the elongate sealing elementand the container body as a single unit, filling the container body witha pourable substance and sealing the container.

[0025] Alternatively, there is provided a method of method ofmanufacturing the single-handed opening mechanism for a containerholding a pourable substance, the method comprising moulding theelongate sealing element, sealing the elongate sealing element to apre-formed container body, said pre-formed container body having twoopen ends and said elongate sealing element being sealed to the first ofsaid ends, filling the container body with a pourable substance throughthe second of said ends and sealing the second end.

[0026] Alternatively, there is provided a method of manufacturing thesingle-handed opening mechanism for a container holding a pourablesubstance, the method comprising forming the elongate sealing elementand the container body as a single unit from a sheet of material, saidsheet of material being scored, folded and sealed to form an open-endedcontainer, filling the container with a pourable substance and finallysealing the open end to form the elongate sealing element.

[0027] The present invention is particularly suitable for single-portioncontainers such as those used for adding milk to tea and coffee.Alternatively, the present invention may be used for largermultiple-portion containers. A preferred embodiment of the presentinvention which also comprises a locking element is particularlysuitable for larger multiple-portion containers.

[0028] Preferred embodiments of the present invention will now bedescribed by way of example with reference to the accompanying drawingsin which:

[0029]FIG. 1 shows a filled and sealed container comprising an openingmechanism according to a first preferred embodiment of the presentinvention;

[0030]FIG. 2a shows the opening mechanism in FIG. 1 in the closedposition;

[0031]FIG. 2b shows the opening mechanism in FIG. 1 in the openposition;

[0032]FIG. 3 shows the openable/closable portion of the openingmechanism in

[0033] FIGS. 1 to 2 b in greater detail;

[0034]FIG. 4a shows a filled and sealed container comprising an openingmechanism with a locking element according to a second preferredembodiment of the present invention;

[0035]FIG. 4b shows the container in FIG. 4a, with the locking elementin a locked position; and

[0036]FIG. 5 shows the opening mechanism in FIGS. 4a and 4 b in greaterdetail.

[0037]FIG. 1 shows a filled and sealed container 1 comprising asingle-handed opening mechanism according to a first preferredembodiment of the present invention. The single-handed opening mechanismcomprises an elongate sealing element 2 which is moveable from a firstclosed position to a second open position. The elongate sealing element2 is deformable and moves from the first closed position to the seconddeformed open position by the application of a squeezing force appliedby the user's hand substantially along the length of the elongatesealing element 2.

[0038] The container 1 is of the single-portion type such as may be usedfor adding milk to tea and coffee. The container 1 has typicaldimensions of 35 mm by 45 mm. The container 1 is preferably manufacturedby forming the opening mechanism and the container body 3 as a singleunit using injection moulding, filling the container body 3 with apourable substance and heat sealing the container body 3.

[0039]FIG. 2a shows the elongate sealing element 2 in FIG. 1 in theclosed position. The elongate sealing element 2 consists of first andsecond substantially rigid portions 4, 5 and an openable/closableportion 6. The openable/closable portion 6 is located between said firstand second substantially rigid portions 4, 5. The openable/closableportion 6 comprises a substantially cross shaped slit 7 in the closedposition. The openable/closable portion further comprises hinge points8, 9, 10, 11 located at the outer points of the cross shaped slit 7. Theelongate sealing element 2 further comprises a breakable diaphragm 12sealing the substantially cross shaped slit 7. The breakable diaphragm12 is broken on moving from the first closed position to the second openposition. The breakable diaphragm could be located either in thevicinity of the upper or lower surfaces of the elongate sealing elementor alternatively, within the cross shaped slit.

[0040] In use, the user applies a squeezing force of F/2 to each end ofthe elongate sealing element 2 and substantially directed along thelength of the elongate sealing element 2. The force F/2 is transmittedalong the substantially rigid portions 4, 5 to the openable/closableportion 6 and the cross shaped slit 7. The cross shaped slit 7 deformsat the hinge points 8, 9, 10, 11, the breakable diaphragm 12 ruptures,and said cross shaped slit 7 opens to form a diamond shaped aperture 13as shown in FIG. 2b. The openable/closable portion 6 opens to form theaperture 13 with limited deformation of the container body 3 and thereis negligible pressure imparted on the contents. Thus the container 1may be opened without spillage and the contents poured in a controlledmanner.

[0041]FIG. 3 shows the openable/closable portion 6 of the elongatesealing element 2 of FIGS. 1 to 3 in greater detail indicating geometricfeatures and forces resulting from squeezing the elongate sealingelement 2. Typical values for the geometric parameters are: L=6.0 mm;b=1.0 mm; B=4.0 mm; w=3.2 mm; T=2.0 mm; diaphragm thickness, t=0.1 mm;e=0.5(B-b/2−(B/2−w/2))=1.55 mm. A typical value for the appliedsqueezing force, F, is F=7 lbs force=31.1 Newtons. The moments at pointA are given approximately by the simplified equation F_(udl)=4.F.e/L².Given the above values for F, e, and L, the opening force on thediaphragm, F_(udl), is 5.36 N/mm, and the tensile force on the diaphragmis given by F_(tensile)=F_(udl)/t=53.6 N/mm². This approximatecalculation is predicted to be within 10% of a more complete finiteelement mesh analysis.

[0042] In this preferred embodiment, when the squeezing pressure isreleased after opening, the openable/closable portion 6 naturallysprings back to an intermediate, ‘semi-closed’ position. Resealing thispreferred embodiment is not of importance as the container is of thesingle-portion type which is thrown away after use.

[0043] This preferred embodiment is made of plastic. Selection of thetype of plastic is based on achieving a number of goals: enoughelasticity to prevent the opening mechanism tearing or fracturing at thehinge points when opened; not too much elasticity that the diaphragmsimply stretches like a balloon without rupturing on moving from thefirst open position to the second closed position; a suitable balance ofyield stress versus malleability so that the diaphragm can be moulded tothe correct thickness with the required breaking stress; chemicallyinert against a range of liquids so that chemicals do not leach out ofthe container; low water absorption and permeability to provide aneffective water barrier and prevent the container going soggy; low costof material; melting temperature within range of existing packagingmachinery.

[0044]FIGS. 4a and 4 b show a filled and sealed container 20 accordingto a second preferred embodiment of the present invention comprising anelongate sealing element 21 with a locking element 22. The single-handedopening mechanism comprises an elongate sealing element 21 which ismoveable from a first closed position to a second open position. Thelocking element 22 is constrained to slide on the elongate sealingelement 21. Sliding the locking element 22 from a first unlockedposition, as shown in FIG. 4a, to a second locked position, as shown inFIG. 4b, pulls the two sides of the openable/closable portion 24together preventing the elongate sealing element 21 from opening on theapplication of a squeezing force.

[0045] The container 20 is of the multiple-portion type and has typicaldimensions of 35 mm wide by 100 mm long. The container 20 is preferablymanufactured by forming the elongate sealing element 21 using injectionmoulding and heat sealing the elongate sealing element 21 to apre-formed container body 23. The pre-formed container body 23 has twoopen ends and the elongate sealing element 21 is heat sealed to one ofthe ends. The container body 23 is then filled with a pourable substancethrough the second of the ends and is heat sealed at the second end.

[0046]FIG. 5 shows the elongate sealing element 21 of FIG. 4a and 4 b inmore detail. The locking element 22 is in the first unlocked positionand the openable/closable portion 6 is in the second open positionforming a diamond shaped aperture 25. Sliding the locking element 22from the first unlocked position to the second locked position pulls thetwo sides of the openable/closable portion 24 together thus closing thediamond shaped aperture 25 and preventing the elongate sealing element21 from opening on the application of a squeezing force. The elongatesealing element 21 may be reopened by sliding the locking element 22back to the first unlocked position and applying a squeezing forcesubstantially along the length of the elongate sealing element 21.

[0047] The locking element is particularly useful as it preventsaccidental opening of the container. For example, a container ofcosmetic cream carried around in a handbag may be subjected to buffetingand squeezing forces. The locking mechanism would ensure that there isno accidental leakage.

[0048] The embodiments described here are formed using injectionmoulding and subsequently heat sealed. However, there are a number ofdifferent plastic moulding processes that may be used includinginjection, vacuum, blow and press. Similarly, there are a number ofsealing processes including heat, glue and crimp.

[0049] Other preferred embodiments of the present invention are alsoenvisaged. For example, a further embodiment of the invention may bemanufactured in which the openable/closable portion automaticallysprings back from the second open position to the first closed positionon releasing the squeezing pressure, thus closing and sealing thecontainer without the need for a locking element. An alternativeembodiment of the present invention may be manufactured by forming theelongate sealing element and the container body as a single unit from asheet of material. The sheet of material would be scored, folded andsealed to form an open-ended container. The container body would befilled with a pourable substance and finally sealed at the open end toform the elongate sealing element. In this embodiment the sealing of theopen end would form the substantially rigid portions of the elongatesealing element.

[0050] While this invention has been particularly shown and describedwith reference to preferred embodiments, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the scope of the invention as defined bythe appended claims.

1. A single-handed opening mechanism for a container holding a pourablesubstance comprising an elongate sealing element which is moveable froma first closed position to a second open position wherein the elongatesealing element is deformable and moves from the first closed positionto the second deformed open position by the application of a squeezingforce applied by the user's hand substantially along the length of theelongate sealing element.
 2. A single-handed opening mechanism asclaimed in claim 1, wherein said elongate sealing element is resealable.3. A single-handed opening mechanism as claimed in claim 1 or claim 2,wherein said elongate sealing element comprises an openable/closableportion, said openable/closable portion being closed in the firstposition and said openable/closable portion defining an aperture in thesecond position.
 4. A single-handed opening mechanism as claimed inclaim 3, wherein said openable/closable portion comprises asubstantially cross shaped slit in the closed position.
 5. Asingle-handed opening mechanism as claimed in claim 3 or claim 4,wherein said openable/closable portion comprises a plurality of hingepoints.
 6. A single-handed opening mechanism as claimed in any of claims3 to 5, wherein said aperture is substantially diamond shaped.
 7. Asingle-handed opening mechanism as claimed in any of claims 3 to 6,wherein said elongate sealing element consists of first and secondsubstantially rigid portions and wherein the openable/closable portionis located between said first and second substantially rigid portions.8. A single-handed opening mechanism as claimed in any previous claim,wherein said elongate sealing element further comprises a lockingelement for locking the mechanism in the first closed position.
 9. Asingle-handed opening mechanism as claimed in claim 8, wherein saidlocking element is constrained to slide on the elongate sealing element.10. A single-handed opening mechanism as claimed in any previous claim,wherein the elongate sealing element further comprises a breakablediaphragm, said breakable diaphragm being broken on moving from thefirst closed position to the second open position.
 11. A single-handedopening mechanism as claimed in any previous claim, wherein the elongatesealing element is fabricated from a plastic material.
 12. Asingle-handed opening mechanism as claimed in any of claims 1 to 10,wherein the elongate sealing element is fabricated from a cardboardmaterial.
 13. A container comprising a single-handed opening mechanismas claimed in any previous claim.
 14. A method of manufacturing asingle-handed opening mechanism for a container holding a pourablesubstance as claimed in any of claims 1 to 10, the method comprisingmoulding the elongate sealing element and the container body as a singleunit, filling the container body with a pourable substance and sealingthe container.
 15. A method of manufacturing a single-handed openingmechanism for a container holding a pourable substance as claimed in anyof claims 1 to 10, the method comprising moulding the elongate sealingelement, sealing the elongate sealing element to a pre-formed containerbody, said pre-formed container body having two open ends and saidelongate sealing element being sealed to the first of said ends, fillingthe container body with a pourable substance through the second of saidends and sealing the second end.
 16. A method of manufacturing asingle-handed opening mechanism for a container holding a pourablesubstance as claimed in any of claims 1 to 10, the method comprisingforming the elongate sealing element and the container body as a singleunit from a sheet of material, said sheet of material being scored,folded and sealed to form an open-ended container, filling the containerbody with a pourable substance and finally sealing the open end to formthe elongate sealing element.
 17. A single-handed opening mechanismsubstantially as herein described with reference to the accompanyingdrawings.
 18. A method of manufacturing a single-handed openingmechanism substantially as herein described with reference to theaccompanying drawings.